Added Disk...

[5PercenterStgAdmin]

Good Morning Everyone... I'm green on the 3 Par and short on time so please forgive the general questions, is it wrong to miss setting up on my EVA? : )

I had a 2 node, 3shelf, 7400, last week HP added 2 more shelves and 70 disk (across all 5 shelves)... I see the space in my MC but I have no clue what to do with it, questions...

1. I currently have only 1 RAID 5 CPG in use for VMFS and Sharepoint. I want to add a 5 TB RDM for VMware SQL Lun, should I add that to that same CPG? I'm good with the RAID 5 but I'm hoping to snapshot that for backups, does that constitute a different CPG?

2. I swear I set up my VVs with redundancy based on the amount of shelves, now that I've gone from 3 -> 5 should I be modify that?

Many Thanks

[Schmoog]

I would say it's not at all wrong to miss your EVA. I came from an EVA background myself, so I completely understand.

With regard to your questions:

1) I would say if you're OK with the settings, there's no need for a separate CPG. One thing that took me a bit to fully get is that a CPG is not equal to a Disk Group in EVA parlance. You can create as many or as few CPG's as you like, and the physical disks can be in multiple CPG's without issue. Generally, HP's best practice is to minimize the number of CPG's as much as possible, as it makes the administrator's life easier, and the array simpler. On my arrays, I have 4 CPG's, 1 each on FC R5 and NL R6 for AO, and 1 each on FC R5 and NLR6 for no AO.

2) as far as snapshots are concerned, it doesn't necessarily constitute a separate CPG, but it is a separate type of space allocation. your VV will reside in the "user space". For snapshots, that is "copy space". So if you don't assign a CPG for copy space, you cannot take snapshots or replicate the VV. Note though that the CPG for copy space can certainly be the same CPG as the user space

3) There should be no need to change the availability parameters to go from 3 to 5. HA Cage should still be just fine.

[afidel]

The only thing I'd add to Schmoog's comments is that if you or HP didn't already do so I would run a tunesys off hours to rebalance your space usage and to get the added performance from your new disks for your existing vvols.

[5PercenterStgAdmin]

Thank you both....

I'm thinking they didn't run a tune system as looking at the % allocated on the disks and I have a bunch at 70% and a bunch under 10%.... That tune is a leveling right?

Do I have to perform that tunesys before I can assign the added space to my CPG? Any good tips on doing that? Having a quick look I've seen some command line solutions, oh how I wish I had time to learn a new command line... I'm going about this rather quickly so I'm hoping to find the spot right I right click and set the new size : )

Thanks again!

[Schmoog]

Yep, tunesys = leveling. And for performance reasons, you should definitely do that.

As far as "assigning space to the cpg" its unnecessary. The cpg will grow as needed.

Also, there is no need to wait for tunesys to complete before using the new disks

[afidel]

CPG's automatically grow into any new disks that meets their definition (which unless you did selected disks (which you should NOT do) means your new disks are already in the CPG). The issue is that only new growth will utilize chunklets on the new disks unless you do a tunesys or a tunecpg.

[Davidkn]

I'd personally create a new cpg with 4+1 and cage ha if you now have 5 shelves full of the same size disks.

At the moment if you have cage ha then you're losing 33% of your storage with a 2+1 raid set.

This could be reduced to 20% with 4+1.

If you have dynamic optimisation then I wouldn't run the tunesys but I'd create the new cpg and create the new volumes in there, and the use do to migrate all your current vvols to the new cpg, that way you level the San in a more controller manner as you can set 1 or 2 vols to move each night rather than pressinggo and wondering how long it will take.

thats my personal preference anyway.